This invention relates in general to color video printer apparatus for producing a color photographic copy of a color video signal. More particularly, this invention relates to microprocessor control for color video printer apparatus which insures proper operation of such apparatus to minimize improper exposure, image degradation and waste of color photographic copies.
In the cross-referenced, commonly-assigned U.S. patent application Ser. No. 776,232, entitled COLOR VIDEO PRINTER, there is disclosed a color video printer for producing a color photographic copy from a color video signal. The printer includes a monochrome display device and an exposure station which is located along an optical path from the display device and at which is located self-processing photographic elements. A color filter wheel has red, green and blue filters which are sequentially movable into the optical path. A video signal circuit provides a color video signal including concurrent red, blue and green component video signals. The video signal circuit is electrically coupled to the display device by means of a selectively actuatable gate which applys to the device only one color component video signal from each field of three color component video signals. A self-processing photographic element positioned at the exposure station, is exposed to a sequence of six color field images produced by the display device and filter wheel, the six color field images constituting a full resolution color frame image having odd and even fields of each of the primary color fields. The printer also includes operator actuatable controls for adjusting the image characteristics of the color video image before making a copy of the image and a color viewer for viewing the color image.
In such a color video printer it is desirable to effect control of the operation of the printer in a simple, economical and efficient manner. It is also desirable to inhibit exposure of a photographic element when the color filter wheel is not synchronized with the field frequency of the color video signal so that improper exposure of and waste of self-processing photographic elements is prevented. It is further desirable to control such a printer so that operator controls for adjusting the characteristics of a color video image prior to copying are not usable during exposure so that exposure parameters are not changed during the exposure sequence in order to prevent image degradation and wasted photographic copies.